It is frequently desirable after twisting one or more yarns to apply a coating of wax or paraffin to such a yarn. This can be done in several ways such as, for instance, shown in German patent publications 1,292,566, 2,105,588, and 2,226,311 (U.S. Pat. No. 2,890,924) by passing the yarn directly over a body of wax or paraffin. Typically a rotating paraffin body is positioned in the path of the yarn downstream of the twister, and means is provided for advancing the body toward the yarn as it is used up.
Such arrangements have two considerable disadvantages. First of all relatively complex drive and feed systems are necessary for the paraffin body. Second, the yarn must be relatively tightly spanned or stretched over such a body in order to ensure good wax transferal from the body to the yarn. Such tight tensioning of the yarn is disadvantageous in many systems wherein the yarn is relatively bulky and weak, or where it is subsequently taken up in a relatively loose yarn package.